An integrated circuit (“IC”) chip or die is a small electronic device limited by the “real estate” available for mounting the packaged chip. Even larger form factor systems, such as PC's, compute servers, and storage servers, need more integrated circuits in the same or smaller “real estate”. Particularly acute are the needs for portable personal electronics, such as cell phones, digital cameras, music players, PDA's, and location-based devices, further driving the need for integrated circuit packaging density.
It is conventional in the electronics industry to encapsulate one or more semiconductor devices, such as IC dies, into semiconductor packages. These semiconductor packages protect the IC dies from environmental hazards and assist in electrically and mechanically attaching the IC dies to other electronic devices. Commonly, such semiconductor packages include metal leadframes for supporting IC dies. A leadframe is a metal frame that usually includes a paddle that supports an IC die after it has been cut from the wafer. The leadframe has lead fingers that provide external electrical connections for the IC die.
An IC die is bonded to the die paddle region, formed centrally on the leadframe. Conductors such as bond wires electrically connect pads on the IC die to individual leads or lead fingers of the leadframe. That is, the IC die is attached to the die paddle, and then bonding pads of the IC die are connected to the lead fingers via wire bonding or flip die bumping to provide the external electrical connections. A hard plastic or epoxy encapsulating material (“encapsulant”) is then applied to form the exterior of the semiconductor package, covering the bond wires, the IC die, and (when present) other associated components.
Although the leadframe is the central supporting structure of the semiconductor package, only a portion of the leadframe is surrounded by the plastic encapsulant. Some portions of the leadframe provide external structure by being exposed or extending beyond the semiconductor package to electrically connect and physically support the semiconductor package.
Once the IC dies have been produced and encapsulated in semiconductor packages, as described above, they may be used in a wide variety of electronic devices. The number and variety of electronic devices utilizing semiconductor packages has grown dramatically in recent years. These electronic devices include personal computers, workstations, compute servers, storage servers, and even more increasingly portable personal electronics.
One example of a semiconductor package is the dual row QFN package, which was designed and developed to increase the number of terminal pads/leads for connection to the other components in these electronic devices. However, as the market demand increased for more applications of the same package, the package required terminal pads/leads in different configurations and this resulted in manufacturing problems.
The semiconductor packages are manufactured in long, wide strips that are singulated, or separated, into individual semiconductor packages. When using mechanical sawing or scribing techniques for singulation, cracks or chipouts are caused by cracks that radiate away from the scribe between the semiconductor packages. In chipouts, a portion of the encapsulant actually breaks out. With cracking, cracks may propagate through the encapsulant and destroy the environmental protection provided by the encapsulant.
These types of defects result in lost revenue when the cracked die is discovered before sale, as well as product failures and dissatisfied customers if the defect in the die is not discovered until after the purchase.
Thus, a need still remains for an integrated circuit package system to provide improved configurability and manufacturing yield. In view of the ever-increasing commercial competitive pressures, along with growing consumer expectations and the diminishing opportunities for meaningful product differentiation in the marketplace, it is critical that answers be found for these problems. Additionally, the need to save costs, improve efficiencies and performance, and meet competitive pressures, adds an even greater urgency to the critical necessity for finding answers to these problems.
Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.